Acute Drug Treatment
The goal of treatment for cluster headache is to decrease the pain, severity, and duration of each attack. Early intervention is critical yet difficult, since a single cluster headache can be as short as 15 minutes. Non-oral routes of administration for medications are therefore preferable.
Oxygen inhalation is the first line therapy for cluster headache. Treatment is initiated with 100% oxygen at max flow rate of 7 to 10 liters per minute. Treatment should continue for 15 minutes. Although up to 70% of patients experience relief within five to ten minutes, some patients report that oxygen suppresses rather than aborts the attack and that pain may return. There are no side effects with this treatment.
Sumatriptan, 6 mg administered subcutaneously is an effective acute treatment for episodic and chronic cluster headaches, but it is most useful for patients who report one or two cluster attacks per day. Cluster attacks usually respond within 10-15 minutes. Smaller doses of two to three mg may also be enough to relieve the attacks. It should be used with a prophylactic so as to avoid dependency.
Intranasal sumatriptan (20 mg) has been shown to have some efficacy but is generally regarded as not being as effective as the subcutaneous injection.
Prophylactic Drug Treatment
The two main goals of preventive treatment for cluster are:
- To rapidly suppress individual attacks
- Maintain that remission throughout the patient’s typical cluster period.
Verapamil is the gold standard in the treatment of Cluster Headache. Treatment can be initiated at 120 mg daily and titrated up to 480 mg a day. Side effects are rare, but constipation is common. Other side effects include dizziness, nausea, edema, bradycardia, fatigue, and hypotension.
Prednisone (60mg a day) and Dexamethasone (4-8mg a day) are fast acting transitional prophylactic drugs that are used (usually in specialist centres) for Cluster headache prophylaxis.
Side effects include insomnia, restlessness, hyponatremia, edema, hyperglycemia, osteoporosis, myopathy, and gastric ulcers. The use of corticosteroids is discouraged in the long term in patients with chronic cluster headaches because the incidence of side effects increases with prolonged use.
Sometimes used in specialist centres, Lithium carbonate has been shown to be effective against episodic and chronic cluster headaches. Of cluster headache patients, 78% of patients with chronic clusters and 63% of patients with episodic clusters respond to lithium. The usual daily dose ranges from 600 to 900 mg in divided doses. Side effects might include tremor, polyuria, and diarrhea. Nephrotoxicity and hypothyroidism can occur with long-term use.